The present invention generally relates to transmissions which transmit power generated by a power source to an output having a load. More specifically, the present invention relates to a continuously variable transmission that includes a gear having a varying size that can be employed in vehicles, as well as other applications.
A transmission is known to convert and transmit power generated by a source to accommodate a load placed on an output of the transmission. Manual transmissions used in vehicles utilize a hand-operated shift lever and foot-operated clutch to enable manually shifting among various gear ratios of the transmission. Automatic transmissions eliminate the combined use of the clutch and shift lever, but result in a loss of efficiency during the transfer of power, as compared to manual transmissions. It is desirable to have a transmission with a continuous, infinite range of gear ratios to more efficiently respond to the various loads placed on the output, but can be operated by a user with the simplicity of an automatic transmission. Such transmissions are know as continuously variable transmissions. It has long been recognized that a continuously variable transmission has the potential to improve a number of different systems utilizing a rotary power source, such as an engine or motor. Compared to common transmissions that have a discrete number of xe2x80x9cstepsxe2x80x9d or gear ratios, the xe2x80x9csteplessxe2x80x9d performance of an ideal continuously variable transmission should improve efficiency in many applications. The disadvantage with current continuously variable transmissions is that most of them employ belts to complete the drive-train or friction clutches to perform gear ratio changes, or even hydraulic pumps to propel a vehicle. Another disadvantage with current manual continuously variable transmissions in vehicles is the undesirable stress on the engine and drive train, due to poor operation by the driver.
It is an object of the present invention to provide a continuously variable transmission which is a purely mechanical drive system within the transmission housing.
It is another object of the present invention to provide a continuously variable transmission that has a numerous range of gear ratios to more efficiently respond to the various loads placed on the transmission of a vehicle.
A continuously variable transmission that includes an input connected to a power source, at least one conical shaped gear, at least one variable ratio gear and at least one variable ratio gear adjustment device for each at least one variable ratio gear. The variable ratio gear engages the conical shaped gear and the variable ratio gear is able to change gear size along the conical shaped gear. The variable ratio gear adjustment device interacts with the variable ratio gear to change the gear size. The variable ratio gear can be a ring shaped collar with an open center and include adjustable gear teeth, which change the gear size of the variable ratio gear. The variable ratio gear adjustment device can be a conical shaped device which inserts into the open center of the collar, such that the collar moves along a height of the conical shaped device to change gear size.